User locked out of campaign

[ardentiasugar]

Hi,

Whilst testing an email campaign (using a 'user' type) I clicked the 'opt out' link by accident. The opt out page that returned stated that sugarcrm users cannot opt out of campaigns (which is what I wanted to happen as I had clicked the link by mistake). However, now I can't seem to re-send my campaign to that sugarcrm user. Could someone tell me how to allow that user to opt back in to the campaign please? I guess it must have been added to a suppression list or something. I couldn't find anything in the database for 'user' types - only 'email_opt_out' fields for 'contacts', 'leads' etc.

Thanks in advance